A Bit of Light Reading on the Hand Raising of Big Cats
This journal article details the socialisation of a single hand reared Sumatran tiger cub and it’s successful reintroduction to its mother:
https://www.ncbi.nlm.nih.gov/pubmed/23282293
Given the drawbacks of hand-rearing nonhuman animals in captivity, the practice is generally avoided, but it is sometimes necessary. A few scientific publications are available to guide managers toward best practices in hand-rearing, but the majority of articles focus on hand-rearing captive primates. Less is known about hand-rearing carnivores, but early socialization appears to be critical for adult social behavior. This article documents the successful hand-rearing and reintroduction of a single female Sumatran tiger cub at Zoo Atlanta. Reintroduction included a systematic procedure that used scent trials and introduction sessions through a barrier to gauge interest and determine whether or not aggression was a problem. Based on signs of interest, reduced stress-related behaviors, and a lack of aggression, animal managers decided to proceed with reintroduction. During the introductions, the animals were not aggressive and did occasionally interact, although typical mother-infant interactions were rare. The cub has since bred naturally and successfully delivered and reared two litters of cubs.
These data suggest limited exposure to an adult tiger may be adequate socialization for normal reproduction even if it is provided relatively late in the cub's development.
This journal article examines the effects of hand rearing on the reproductive success of captive large cats (Siberian tiger, cheetah, snow leopard and clouded leopard):
https://www.ncbi.nlm.nih.gov/pubmed/27214261
Species Survival Plans and European Endangered Species Programmes have been developed for several species of endangered felids in order to build up captive reserve populations and support their conservation in the wild. The Siberian tiger (Panthera tigris altaica), snow leopard (Uncia uncia), cheetah (Acinonyx jubatus) and clouded leopard (Neofelis nebulosa) are managed in such ex situ conservation programmes. Many zoological institutions hand-rear offspring if rearing by the mother fails. Hand-rearing can cause behavioural problems, resulting in decreased copulation and lower breeding success in some species. In this study, studbook data subsets were examined: from 1901 to 2011; and 2000 to 2011. We analysed records from 4273 Siberian tigers, 2045 snow leopards, 3435 cheetahs, and 804 clouded leopards. We assessed the number of offspring produced, litter size, age at first reproduction, longevity, infant mortality and generational rearing of hand-reared versus parent-reared individuals.
Hand-reared Siberian tigers (p<0.01; p = 0.0113), snow leopards (p<0.01), male cheetahs (p<0.01) and female clouded leopards (p<0.01) produced fewer offspring than parent-reared individuals. Hand-reared snow leopard breeding pairs had larger litters than parent-reared pairs (p = 0.0404). Hand-reared snow leopard females reproduced later in life (p<0.01). Hand-reared female Siberian tigers lived shorter lives, while hand-reared cheetahs lived longer (p<0.01; p = 0.0107).
Infant mortality was higher in hand-reared snow leopards (p<0.01) and male cheetahs (p = 0.0395) in the 1901-2011 dataset and lower in hand-reared female Siberian tiger and male snow leopard cubs (p = 0.0404; p = 0.0349) in the 2000-2011 dataset. The rearing of the mother and subsequent rearing of offspring showed a significant relationship for all species (p<0.01 for Siberian tiger and snow leopard cubs; p<0.001 for cheetah and snow leopard cubs). Taking into account the limited carrying capacity of zoos, the results of this study highlight that careful consideration should be taken when deciding whether or not to hand-rear individuals that are part of Species Survival Plans and European Endangered Species Programmes.
This book, regarding the introduction of dogs, had a section in the preface about big cats, who the author worked with from 1994 at Taronga Zoo:
https://books.google.co.nz/books?id=7XnVBgAAQBAJ&printsec=frontcover&dq=isbn:1617811602&hl=en&sa=X&ved=0ahUKEwii4o-K5-DYAhUEzbwKHUJKAWEQ6AEIJzAA#v=onepage&q&f=false
Solitary species are at a higher risk of poor socialisation in zoos. As a young keeper, I saw one year old big cats removed from the mother so that she could breed again. At one year of age, these cats are not ready to live a solitary life.
The longer they spend alone at this early stage of their life, the harder it will be to introduce them to a breeding partner later. This was particularly true of hand reared cats. One tiger (Kemiri) that I knew was hand reared by keepers and as a result of a lack of socialisation with her own species, failed to ever be able to introduced safely to another tiger. She just didn’t have the range of tiger social behaviours to make other tigers feel at ease and every attempt to pair her up with a male ended up with the male attacking her.
Very early on, my policy was to leave cubs or young of any species with their mother (or parents where possible) for at least one or two years past normal age of dispersal with the goal of only transferring the young to another zoo once it had a mate waiting for it. If this was not possible, as timing of animal transfers can be difficult for various reasons – then with good early solid socialisation, past the usual age of dispersal, the animal had a good foundation that would carry it through even if there was a six month lag in meeting another of its own species.
Light Discussion
The Australasian region provides many examples of the three different types of rearing of big cats: parent raised, hand raised and peer raised. As noted in the first article, the reintroduction of the Sumatran tiger to its mother was its ultimately successful. While the mother and cub did not develop the typical parent/offspring relationship, it clearly provided critical socialisation which allowed the cub to develop into a socialised adult, capable of rearing its own offspring without human assistance. In contrast, Kemiri, who was born at the Taronga Zoo in November 1994 and was hand raised by zoo staff, did not have the opportunity to socialise with her own species and as noted in the book above, this led to her being unable to introduced to the male tiger at the Adelaide Zoo. Unlike the tiger cub described in the first journal article, Kemiri was never reintroduced to her mother Selatan, who gave birth 11 months later to her second litter. If reintroduction to the mother is not possible, the saving grace for a cub can often be its siblings, which upgrade its rearing/socialisation from hand raised to hand raised-peer raised. Unfrotuantely for Kemiri, this was not possible. Her littermate died in their first week, leaving Kemiri a single cub.
In April 2008 at the Perth Zoo, newborn Sumatran tiger Sali found herself in a similar situation. Her mother Setia gave birth to a litter of four cubs, but when three died shortly after birth, she rejected the fourth. The decision was made to transfer Sali at six weeks of age to Dreamworld on the Gold Coast, where their Sumatran tigress, Soraya, was heavily pregnant. Soraya delivered triplets in due course and Sali, only a few weeks older, was hand raised alongside them. As with all tiger cubs at Dreamworld, she was also introduced to a large cross section of sub adult and adult tigers of a range of ages, allowing her excellent socialisation opportunities. This ultimately paid off, with Sali being transferred to Hamilton Zoo in 2012, and after being successfully introduced to the mother reared male Oz, producing two cubs in 2014. Sali has reared both cubs well and despite having a closer relationship with her keepers than you’d expect from a mother reared tiger, shows no behavioural signs of being hand raised.
When Kemiri was born in Novemeber 1994, there were few zoos holding Sumatran tigers, let alone breeding them. The last litter born had been in 1990, and there would be only two further litters born that decade (in 1995 and 1996). It initially appears understandable that the breeding programme was unable to socialise her with same age Sumatran tigers cubs as was provided for Sali in 2008, in the height of a Sumatran tiger baby boom in the region, but frustratingly there was in fact an excellent opportunity. Tiger Island opened in early 1995, with the arrival of six Bengal tiger cubs, born between November and December 1994. This would have been an ideal opportunity for Kemiri and without a doubt would have provided her with the socialisation she never had.
Many zoos in the region have hand raised litters of African lion cubs. Hunter Valley’s male lion Jambo was hand raised alongside his two sisters in 1999 and went on to be paired successfully with a lioness at the Taronga Zoo, producing two cubs in 2003. Sheeka, born 1999 at the Mogo Zoo, was hand raised with initially own a dog for socialisation. Before she was a year old, Sheeka joined a similar aged mother raised cub, Kura, at the Auckland Zoo which provided invaluable education on natural lion behaviour. Upon Sheeka’s death last year, Auckland Zoo commented that “Sheeka was very different in personality to any other lions. She could be a little vague and off in her own world at times, but she seemed to really enjoy her relationship with her keepers and was always pleased to see us.” While Sheeka never fully acted as a mother raised lioness would, the socialisation she was provided through her introduction to Kura ensured she lived a full filling life as a member of Auckland Zoo’s pride. The last time I saw Sheeka, she was sleeping in the sun alongside either Kura or Amiria. Sheeka may have biologically been on the outside of Kura and Amira’s mother-daughter relationship, but socially she was as much a part of the pride as either of them.
The preface of the book mentioned above describes the benefits of allowing cubs to remain with their mother/family group beyond the natural age of dispersal. Due to adequate nutrition among other factors, Sumatran tigresses in a captive setting often come into season around 12 months after the birth of their cubs, well before the natural age of dispersal. Wellington Zoo separated their breeding female, Cantic, from her two litters (born 1996 and 2000) around this age as she was becoming aggressive to them. This was likely the reason Selatan’s second litter (born 1995) were also shifted on to Taronga Western Plains Zoo at a similar age. These days, it’s more common for zoos in the Australasian region to give the mother a contraceptive, which allows her to tolerate the presence of her cubs well into adulthood. This was done with Molek at the Auckland Zoo, who gave birth in 2008 and still lives with one of her cubs and also at the Taronga Zoo. Assiqua gave birth in 2003 and her litter remained with her for four years until 2007. Her daughter Jumilah gave birth in 2011 to triplets and still lives with two of her cubs.
In 2016, the Werribee Open Range Zoo made the seemingly bizarre decision to introduce their soon to leave adolescent African lion cubs to their three month old half siblings. This appeared a risky decision, but the zoo justified it was good education for the young males by providing them with experience with young cubs. Whether this socialisation experience will benefit the young males, should they ever produce cubs of their own remains to be seen. Orana Wildlife Park attempted to establish a pride in the early 2000s with a male Toby (hand raised-peer raised) and females Priscilla (hand raised) and Kiara (unknown). After Priscilla gave birth to twins in 2002, she was reintroduced to the pride, where Toby attacked the female cub, to the point where she had to be euthanised. Of course many factors could have led to this, including the possibility that Toby was an unusually aggressive male or the introduction caught him on a bad day, but it is interesting to note Toby never had any experience with younger cubs prior to arriving at Orana Widlife Park. Another contributing factor could have been the inability of the hand raised mother, Priscilla to pre-empt warning signs of aggression from Toby, something a mother raised lioness may have recognised and acted on. After this, Toby was kept separate from the females and cubs, and only introduced to the females for breeding. He died in 2006 at the age of eight.
The second journal article identifies a strong relationship between the rearing of the offspring and the subsequent rearing of their offspring. Orana Wildlife Park has excelled in breeding cheetah, raising several cubs to adulthood since 1993, all from the same family. The last two generations (born 2009 and 2014) were both hand raised after being rejected by their mother. The generation prior to this (born 2004) were initially mother raised but orphaned around the age of 3 months and were peer raised (but not hand raised) by zoo staff who allowed the cubs to develop on their own with minimal interference as they were just approaching the age of weaning and eating solids.
The same journal article also turns up some surprising and seemingly unexplainable results including the fact hand reared snow leopard pairs produced larger litters than mother reared pairs and that hand raised Siberian tigresses live shorter lives than their mother raised counterparts. The dataset in our region is probably too small to draw any conclusions on this hypothesis but I’m pleased to note that despite never being able to be paired with a male or rear her own litter of cubs, Kemiri the hand raised tiger did not live a short life. She died in June 2017 aged 22 years and currently holds the record for longevity in the region.
